The present invention relates to a filtrating apparatus for normally, continuously filtrating foreign matters such as yeast funguses which are contained in beer during a beer producing process. It relates more particularly to a filtrating apparatus which is capable of recycling a filter in an in-line manner.
Recently, in the beer producing process, it is necessary to filtrate the beer, which has been subjected to a so-called post-fermentation, to remove funguses from the beer. In this case, after a preprocess filtration using a filter aid such as diatomaceous earth and the like has been effected, a finishing filtration is further effected. At this time, it is generally well known to use a resin (or synthetic resin) made cartridge filter as a filter medium for a direct filtration.
However, since the resin made cartridge filter has a low mechanical strength, there is a fear that the filter would be damaged if the flow rate and pressure conditions would be worse. Also, it would be impossible to effect a strong physical washing such as flashing.
In view of the characteristics of the material and the structure, there is a fear of a damage of the filter or a fear of residual chemicals, and hence, a chemical washing using chemicals is not normally performed. In general, the filtration resistance would be large so that a desired filtrated flow rate per one unit area could not be attained. In view of a damage at a high temperature, it would be impossible to sterilize the apparatus having the filter with steam kept at about 120.degree. C. or more.
Accordingly, in general, it is difficult to recycle or regenerate the resin made cartridge filter. Such a filter is used as a disposable one. It is thus necessary to effect an interchanging work which could not be attained in an automatical manner. At the same time, since the running cost would be increased, it is desired to develop beer filters instead of the conventional filters. Also, as described before, it is impossible to increase the filtration flow rate per one unit area in such a resin made cartridge filter. In order to increase the amount of processed beer, it is necessary to increase a filteration area, which will lead to an enlargement of the apparatus per se. On the other hand, in a method using the assistant chemicals, it is necessary to provide an extra equipment relative to the assistant chemical process. In this case, the apparatus would be enlarged in size and it would be impossible to make the apparatus compact.